Instruction manual

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3.5.3 Selecting Scanning Speed
Eight scanning speeds are available with four buttons.
To select a scanning speed, click one of the Scan speed icons
on the
control panel.
Two scanning speeds are assigned to each button. They are set alternately by clicking the button.
Totally 14 scanning speeds are available for image observation. The assignment of scanning
speeds to four buttons can be customized. Refer to <2.3.5.3 Scan Control block>
The Run/Freeze
( )
button on the Scanning Image window changes run (irradiate
and scan electron beam on the specimen, and continuously acquire image) and freeze (blank
electron beam and stop image acquisition ) status alternately. While electron beam is scanning,
the string “RUN” is blinking at the upper-left corner of the scanning image. When the RUN button
is clicked, scanning stops after continuing scan until it reaches to the end of the frame. The string
“Going to Freeze” blinks and then, it changes to “Freeze”.
(1) TV Scanning:
TV Scanning of flicker-free images is convenient for a field search of the specimen, coarse
focus, etc. The quality (S/N ratio) of the image is improved by frame averaging.
Two Fast Scanning speeds, TV1 and TV2, operate at the same speed but allow different
number of frames to be averaged for each are available.
To set the number of frames to be averaged, use the Image tab in the Setup dialog window. In
the FAST SCAN AVERAGING area, set TV1 and TV2 value. Recommended numbers are 4
for TV1 and 8 or 16 for TV2. The higher the number of frames, the better the attainable image
quality.
The TV scanning runs with 640x480 pixels only. When used in full screen mode, the image
size is reduced to half.
(2) Fast Scanning:
Fast Scanning runs with a half speed of TV scanning. It is also convenient for a field search of
the specimen, coarse focus, etc.
The full size image is displayed when used in full screen mode.
The quality (S/N ratio) of the image is improved by frame averaging.
Two Fast Scanning speeds, FAST1 and FAST2, operate at the same speed but allow different
number of frames to be averaged for each are available. To set the number of frames to be
averaged, use the Image tab in the Setup dialog window. In the FAST SCAN AVERAGING
area, set TV1 and TV2 value. Recommended numbers are 2 or 4 for FAST 1 and 4 or 8 for
FAST 2.
(3) Slow Scanning: